Beijing should implement punitive measures to counter government exchanges between Washington and Taipei, such as forbidding senior US officials who visit Taiwan from entering the Chinese mainland, and voting against US-supported resolutions at the UN, analysts said.

Alex Wong, deputy assistant secretary at the Bureau of East Asian and Pacific Affairs from the US Department of State, arrived in Taipei Tuesday night for a three-day visit. Wong is the first US government official to visit Taiwan following the enactment of the US' Taiwan Travel Act, which encourages high-level exchanges between Washington and Taipei.

According to a statement from the American Institute in Taiwan, the organization representing the US government in the absence of formal relations, Wong will "hold discussions with Taiwan authorities on a wide range of matters important for the US-Taiwan relationship," the statement read.

Apart from Wong, Kaohsiung Mayor Chen Chu also embarked on a visit to the US last week to deliver a speech at the Washington-based Center for Strategic and International Studies.

"Despite coming from the Department of State, Wong's government rank is not very high. Exactly how much sway he holds in US' Asia policy development isn't known but his visit to Taiwan has symbolic implications. Taiwan may even view it as a breakthrough," Zhang Wensheng, a professor at the Taiwan Research Institute of Xiamen University, told the Global Times.

Analysts fear that Wong's visit is part of efforts by Washington and Taipei to pave the way for higher-level meetings.

Beijing is also concerned that other countries, such as Japan and European nations, might follow suit and establish high-level official exchanges with Taiwan.

"One of the options is to ban US officials that have visited Taiwan from visiting the Chinese mainland. Beijing can also downgrade official communications with specific US bodies that interact with Taiwan, for example, reducing or suspending interaction with the Bureau of East Asian and Pacific Affairs," Zhang said.

He also noted that Beijing can refuse to cooperate with Washington on certain UN resolutions to send a signal to the world Beijing's attitude on the Taiwan question.

As for Taiwan, analysts said the Chinese mainland may move to further isolate Taiwan by establishing ties with Taiwan's few "diplomatic" partners.

Unspoken redline

The Chinese foreign ministry on Wednesday denounced the Taiwan Travel Act.

Foreign ministry spokesperson Hua Chunying said China has lodged a stern representation to the US regarding US officials' visit to Taiwan. She said China urges the US to abide by the one-China policy and the three joint communiqués, stop any form of official interaction with Taiwan to prevent any serious damage to Sino-US relations and cross-Straits peace and stability.

"There have been other visits by US officials to Taiwan in the past. Some were off the record and some took place when cross-Straits relations were better, and Beijing preferred not to embarrass the sitting leader. With Tsai in office, the mainland's patience with official exchanges between the US and Taiwan is particularly thin," Zhang said.

Relations across the Taiwan Straits sank to a new low after Tsai took office in 2016.

Tsai, chairwoman of pro-independence Democratic Progressive Party, refuses to acknowledge the 1992 Consensus, which emphasizes the one-China principle. Beijing considers the one-China principle the cornerstone of cross Straits relations.

Beijing views visits to Taiwan by a US president, vice president, secretary of state, defense minister and head of the National Security Agency as an unspoken redline, analysts said.

"If Washington allows Tsai to visit the US or allows the defense ministers from both sides to meet in person, current Sino-US relations would be disrupted and another Taiwan Straits crisis may be triggered," Xin Qiang, deputy director of the Center for US Studies at Fudan University, told the Global Times.

In 1995, in response to then Taiwan leader Lee Teng-hui's visit to the US, the mainland conducted exercises that included testing missiles in waters surrounding Taiwan and mobilizing forces in East China's Fujian Province, which is located directly across the straits from Taiwan island.